1. Field of the Invention
The present invention relates to a crossed tapered roller bearing.
2. State of the Prior Art
Such a bearing is known from FR-A-2,032,171. It comprises two coaxial rings disposed one around the other and each defining, in confronting relation, a concave annular surface having a V-shaped section defining two tapered raceways. An even number of tapered rollers is disposed between these two rings. Every other tapered roller is interposed by its lateral wall between one of the raceways of one of the rings and the raceway located in an axially opposed position on the other ring. The other tapered rollers, alternating with the first mentioned rollers, are interposed by their lateral wall between the other two raceways. To permit the assembly, one of the rings is in two parts, each of which defines one of the raceways. Further, for guiding the rollers, the angle of the V of the outer ring is in the neighbourhood of 90.degree. and each tapered roller has a crowned large base whose peripheral edge bears against the raceway of the outer ring against which its lateral wall does not bear.
This type of rolling bearing has a number of advantages, in particular: compactness, ease of assembly, large resistance to tilting torques, i.e. torques which tend to cause one of the rings to pivot relative to the other about a diameter, large axial and radial load acceptance, ease of adjustment of the clearance by the surfacing of one or of both of the confronting surfaces of the two semi-rings constituting the ring made in two parts, no roller cage required, etc.
However, notwithstanding these advantages, the crossed roller bearing has not been the subject of practical applications up to the present time due to problems of the guiding of the rollers. It has been found in certain applications that an exaggerated wear occurs on the edge of the large base of the rollers which is in sliding contact with one of the raceways of the outer ring for guiding the roller. It has also been found that, in some cases, notwithstanding the guiding by the crown surface, the rollers assume a skewed position and jam the bearing.